Parasitic draw - What are the more common culprits?
02-16-2019, 12:10 PM
#52
Stop blaming the battery. 
It's the current being constantly sucked out of the battery that's killing it. And you've determined that's the draw from the (unnecessary) aftermarket car alarm. But if you insist buy a "premium" battery and subject it to the same abuse.
The Mazda battery at 12.5vDC ain't fully charged but that's a normal drop after a week. Batteries self-discharge and don't forget that car also has things connected to the battery all the time -- as does every car in the past couple of decades with remote locks and radio memory. In my small travel trailer the battery won't last more than 2 or 3 weeks before it's dead. There a LP detector wired directly to the battery as well as the memory for the radio. Draw there is in the 150ma range, even higher than yours. In this case, however, I merely switch the battery disconnect to Off when I leave it.
I've personally used the PriorityStart on three (3) different Ford SUVs (which are notorious for dead batteries the way I use the vehicles). They last a couple of years before they themselves fail but will keep enough power in the battery to start the car. I kept the radio stations handy in those SUVs as I needed to reset them when this happened.
Flanders is correct that even a battery that shows a good voltage (charge) may fail to start the vehicle. Load tester (previously mentioned) is maybe $20 at Harbor Freight or Amazon. They all seem to be made in the same PRC factory with different stickers on them. But they'll just confirm what you already know: the battery is damaged beyond repair.
-- Chuck
It's the current being constantly sucked out of the battery that's killing it. And you've determined that's the draw from the (unnecessary) aftermarket car alarm. But if you insist buy a "premium" battery and subject it to the same abuse. The Mazda battery at 12.5vDC ain't fully charged but that's a normal drop after a week. Batteries self-discharge and don't forget that car also has things connected to the battery all the time -- as does every car in the past couple of decades with remote locks and radio memory. In my small travel trailer the battery won't last more than 2 or 3 weeks before it's dead. There a LP detector wired directly to the battery as well as the memory for the radio. Draw there is in the 150ma range, even higher than yours. In this case, however, I merely switch the battery disconnect to Off when I leave it.
I've personally used the PriorityStart on three (3) different Ford SUVs (which are notorious for dead batteries the way I use the vehicles). They last a couple of years before they themselves fail but will keep enough power in the battery to start the car. I kept the radio stations handy in those SUVs as I needed to reset them when this happened.
Flanders is correct that even a battery that shows a good voltage (charge) may fail to start the vehicle. Load tester (previously mentioned) is maybe $20 at Harbor Freight or Amazon. They all seem to be made in the same PRC factory with different stickers on them. But they'll just confirm what you already know: the battery is damaged beyond repair.
-- Chuck
03-02-2019, 11:09 AM
#53
Thread Starter
Stop blaming the battery. It's the current being constantly sucked out of the battery that's killing it. And you've determined that's the draw from the (unnecessary) aftermarket car alarm. But if you insist buy a "premium" battery and subject it to the same abuse.
The Mazda battery at 12.5vDC ain't fully charged but that's a normal drop after a week. Batteries self-discharge and don't forget that car also has things connected to the battery all the time -- as does every car in the past couple of decades with remote locks and radio memory. In my small travel trailer the battery won't last more than 2 or 3 weeks before it's dead. There a LP detector wired directly to the battery as well as the memory for the radio. Draw there is in the 150ma range, even higher than yours. In this case, however, I merely switch the battery disconnect to Off when I leave it.
I've personally used the PriorityStart on three (3) different Ford SUVs (which are notorious for dead batteries the way I use the vehicles). They last a couple of years before they themselves fail but will keep enough power in the battery to start the car. I kept the radio stations handy in those SUVs as I needed to reset them when this happened.
Flanders is correct that even a battery that shows a good voltage (charge) may fail to start the vehicle. Load tester (previously mentioned) is maybe $20 at Harbor Freight or Amazon. They all seem to be made in the same PRC factory with different stickers on them. But they'll just confirm what you already know: the battery is damaged beyond repair.
-- Chuck
It's the current being constantly sucked out of the battery that's killing it. And you've determined that's the draw from the (unnecessary) aftermarket car alarm. But if you insist buy a "premium" battery and subject it to the same abuse.The Mazda battery at 12.5vDC ain't fully charged but that's a normal drop after a week. Batteries self-discharge and don't forget that car also has things connected to the battery all the time -- as does every car in the past couple of decades with remote locks and radio memory. In my small travel trailer the battery won't last more than 2 or 3 weeks before it's dead. There a LP detector wired directly to the battery as well as the memory for the radio. Draw there is in the 150ma range, even higher than yours. In this case, however, I merely switch the battery disconnect to Off when I leave it.
I've personally used the PriorityStart on three (3) different Ford SUVs (which are notorious for dead batteries the way I use the vehicles). They last a couple of years before they themselves fail but will keep enough power in the battery to start the car. I kept the radio stations handy in those SUVs as I needed to reset them when this happened.
Flanders is correct that even a battery that shows a good voltage (charge) may fail to start the vehicle. Load tester (previously mentioned) is maybe $20 at Harbor Freight or Amazon. They all seem to be made in the same PRC factory with different stickers on them. But they'll just confirm what you already know: the battery is damaged beyond repair.
-- Chuck
Old, questionable battery 5 days after sitting:
New replacement battery - 5 days after sitting
There's no doubt that my car is drawing a bit more current in its off state than average. But, the previous "new" battery was a massive point of failure to begin with.
03-03-2019, 06:31 AM
#54
Glad you got the situation, more-or-less, fixed. Need to run the car for a good 30-60 minutes on the freeway, to fully charge the battery. Then, see how the voltage drops over time.
03-04-2019, 08:26 AM
#55
Good for now and I hope it works out but let us know in 6 months -- or maybe two weeks. You're replacing the worn out part (battery) not stopping the cause of the wear. Starting batteries only get a small, finite number deep discharges before they're toast. This one is down to ~70% charge in 5 days. Not in the abuse category yet.
For curiosity I measured my 2.5 year old S2000 battery voltage a few minutes ago. No aftermarket alarm on my car. Measured 12.35vDC after sitting for 14 days. Same power loss as yours but took 3 times as long.
-- Chuck
and I hope it works out but let us know in 6 months -- or maybe two weeks. You're replacing the worn out part (battery) not stopping the cause of the wear. Starting batteries only get a small, finite number deep discharges before they're toast. This one is down to ~70% charge in 5 days. Not in the abuse category yet. For curiosity I measured my 2.5 year old S2000 battery voltage a few minutes ago. No aftermarket alarm on my car. Measured 12.35vDC after sitting for 14 days. Same power loss as yours but took 3 times as long.
-- Chuck
03-04-2019, 08:54 AM
#56
Thread Starter
Good for now and I hope it works out but let us know in 6 months -- or maybe two weeks. You're replacing the worn out part (battery) not stopping the cause of the wear. Starting batteries only get a small, finite number deep discharges before they're toast. This one is down to ~70% charge in 5 days. Not in the abuse category yet.
For curiosity I measured my 2.5 year old S2000 battery voltage a few minutes ago. No aftermarket alarm on my car. Measured 12.35vDC after sitting for 14 days. Same power loss as yours but took 3 times as long.
-- Chuck
and I hope it works out but let us know in 6 months -- or maybe two weeks. You're replacing the worn out part (battery) not stopping the cause of the wear. Starting batteries only get a small, finite number deep discharges before they're toast. This one is down to ~70% charge in 5 days. Not in the abuse category yet.For curiosity I measured my 2.5 year old S2000 battery voltage a few minutes ago. No aftermarket alarm on my car. Measured 12.35vDC after sitting for 14 days. Same power loss as yours but took 3 times as long.
-- Chuck
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